GREEN THUMBS UP: Spring Pruning of Trees and Shrubs

By Suzanne Mahler

Saturday

Mar 18, 2017 at 3:00 PM

Outside my window, light snow is falling, coating my lawn and gardens with a blanket of winter white on this gloomy Friday morning, sadly concealing the welcome signs of spring, but offering protection for tender new growth as another weekend of record-breaking, frigid temperatures sets in. Although the snowdrops and crocuses will eventually reappear, it may be sometime before the ground is free of its crystalline covering with more snow predicted for the coming week.

Throughout the South Shore, winter storms and high winds have toppled trees and split, severed, or cracked large trunks and branches, damaging property, and blocking byways. In some instances, the appearance of our home landscapes has been dramatically changed for years to come.

The ongoing drought, although somewhat alleviated in recent months, has taken a toll on all our plants, but mature trees have been particularly hard hit, struggling to draw sufficient moisture and nutrients to maintain their many limbs. Defoliation by caterpillars has further weakened these woody plants. In their effort to survive, older branches have been sacrificed in favor of new growth leading to innumerable dead branches, but many large trees and shrubs have been unable to recover leading to their eventual demise.

Gusty, swirling winds have scattered branches throughout my landscape, as Mother Nature seems intent on speeding up the pruning process. Each time I venture into the backyard to fill my birdfeeders, I find it necessary to gather tarps full of sizeable branches from my river birch and cherry trees and I am often startled by the sound of large tree limbs or entire trunks cracking and crashing in the nearby woods.

While the lingering snow cover may limit our spring cleanup, this is an ideal time to survey your property’s trees and shrubs and begin the annual pruning process. Cracked or split limbs should always be pruned as soon as they are noticed and time permits since jagged cuts tend to collect water, potentially leading to disease. Partially broken tree limbs, if left dangling, may eventually cause the protective bark of the trunk to be stripped beneath the tear or the branches may fall from the overhead canopy onto smaller ornamental trees and shrubs below, crushing and breaking their branches. The bark of a tree is analogous to our own skin. If the outer layer is damaged, the vital inner trunk becomes susceptible to infections or insects. Since it is considerably easier to view the architecture and damaged branches of deciduous trees and shrubs before they leaf out, early spring is considered the preferred time of year to prune many of these dormant plants.

As you examine your trees and shrubs for dead, diseased, or damaged limbs, look for crossed branches. A tangle of limbs may begin to rub against one another creating wounds in the bark. Crossed branches often lead to permanent distortion or dieback of one or both limbs and create the potential for infections; at least one of the limbs should be removed to prevent further damage.

To ensure precise pruning, the acquisition of quality pruning tools is essential. Inexpensive pruners tend to produce ragged cuts because they are easily bent out of shape. Bypass pruners and loppers tend to be preferred by nurserymen, their scissors-like action enabling cleaner cuts that facilitate the healing process. High quality pruners, like the Swiss-made Felco, are worth the additional cost for their durability and precision. Avoid anvil-style pruners that have one sharp blade with an opposing flat blunt edge as these may crush stems and produce uneven cuts. Hand pruners are preferred for smaller branches up to half an inch across. Long-handled lopping shears are useful for cutting larger branches up to 2-inches thick. Curved-blade pruning saws are ideal for larger branches and great for tight places.

Nearly all woody plants benefit from routine pruning to train and revitalize their growth or to retrain those that have become overgrown to keep them in scale with their surroundings. Regular pruning improves the health of most plants by promoting air circulation and allowing light to reach the interior of an otherwise densely-branched tree or shrub.

While many gardeners should be capable of pruning small trees and shrubs, seek assistance from an insured, qualified tree service company or arborist for larger trees to ensure personal safety and minimize potential hazards to your surrounding plantings and property.

— Suzanne Mahler is an avid gardener, photographer and lecturer who has been developing the 1.5-acre property surrounding her home in Hanover for more than 30 years. Her weekly gardening column ‘Green Thumbs Up’ has appeared in GateHouse Media New England newspapers for more than a decade. She is a member of a local garden club, past president of the New England Daylily Society, an overseer for the Massachusetts Horticultural Society and is employed at a garden center.